A study in The Astrophysical Journal suggests that a mid-sized black hole or a pulsar within one of the brightest globular clusters in our Milky Way galaxy may be the source of enigmatic radio signals. This potential discovery of a black hole emitting radio signals is unprecedented. The signal was detected during observations of the 47 Tucanae cluster, using the Australia Telescope Compact Array (ATCA) in New South Wales, as reported by Space.com.
Globular clusters, ancient star clusters scattered throughout the Milky Way, are known for their dense star populations. 47 Tucanae, in particular, contains over a million stars within a diameter of 120 lightyears and is visible to the naked eye.
The International Centre for Radio Astronomy Research (ICRAR) conducted extensive research on 47 Tucanae, compiling 450 hours of radio data using the ATCA. This led to the creation of a detailed image of the cluster and the discovery of an unusual radio wave source at its center, approximately 14,500 lightyears from the Sun. Researchers suspect that this signal could be emanating from a mid-sized black hole or a pulsar.
Lead author of the study, Alessandro Paduano, a former PhD student at Curtin University in Perth, Australia, highlighted the significance of this potential discovery, noting that while intermediate-mass black holes are theorized to exist in globular clusters, none have been conclusively identified yet.
Mid-sized black holes are considered the elusive link between stellar black holes, remnants of massive stars, and the supermassive black holes found at the centers of galaxies, which can have masses of millions to billions of suns.
Tim Galvin, a research scientist at CSIRO and co-author of the paper, commented on the challenges and excitement brought by this project in pushing the boundaries of their data management and processing software. He remarked on the rich scientific insights made possible by these techniques.
Arash Bahramian, an astronomer at the Curtin Institute of Radio Astronomy overseeing the project, reflected on the promising potential these findings have for future radio astronomy, hinting at the advancements expected with the next generation of radio telescopes.